1. Field
The present application relates generally to the transmission of information over a distribution network, and more particularly, to methods and apparatus for improved frequency tracking of a received signal.
2. Background
Data networks, such as wireless communication networks, have to trade off between services customized for a single terminal and services provided to a large number of terminals. For example, the distribution of multimedia content to a large number of resource limited portable devices (subscribers) is a complicated problem. Therefore, it is very important for network administrators, content retailers, and service providers to have a way to distribute content and/or other network services in a fast and efficient manner and in such a way as to increase bandwidth utilization and power efficiency.
In current content delivery/media distribution systems, real time and non real time services are packed into a transmission frame and delivered to devices on a network. For example, a communication network may utilize Orthogonal Frequency Division Multiplexing (OFDM) to provide communications between a network server and one or more mobile devices. This technology provides a transmission frame having data slots that are packed with services to be delivered over a distribution network as a transmit waveform.
Typically, the transmission frame is delivered over a network as a transmit waveform. Devices in communication with the network acquire and track the waveform so that the transmitted content can be recovered. Unfortunately, conventional systems may take some time to acquire and track the waveform. For example, if a residual frequency error at the end of time division multiplexed pilot signals provided for synchronization is high, then the data modulation may not be properly decoded. Hence it is very important that the frequency error and timing error be minimized at the receiver before the commencement of data demodulation.
Therefore it could be desirable to have a system that operates to quickly acquire and track the frequency and timing of a received waveform so that information encoded in the waveform can be accurately decoded.